This invention relates generally to what is referred to in the industry as "cable tray" system used to support electrical wiring, cables and conduit, and more particularly to a lightweight cable tray system which is especially adapted for supporting data transmission lines and the like.
For years electrical contractors have used cable tray to support electrical cables and the like in elevated position. One type of conventional cable tray comprises a ladder-like structure made of two parallel rails connected by a series of rungs, typically supported from overhead beams by vertical rods or hangers. This system is of relatively heavy-duty construction for supporting relatively heavy electrical conductors, cable, conduit and the like, and is particularly suited for new construction rather than rehabilitation of existing buildings. Another type of cable tray comprises a single center rail having a series of arms extending laterally outwardly from opposite sides of the rail. The single center rail is also typically supported by vertical rods or hangers.
The aforementioned types of cable tray are not especially suited for the burgeoning computer and telecommunications industries where a typical installation involves thousands and perhaps millions of runs of data transmission lines, and they are especially ill-equipped for jobs involving the rehabilitation and modernization of existing buildings to include new telephone, computer and other telecommunications systems. In such buildings, there is often insufficient horizontal space between existing ductwork, columns and other structural members to install sufficient cable tray of existing design to carry the multiplicity of lines associated with the new systems being installed in the building. Conventional cable tray systems are too bulky, too inflexible in their ability to snake through existing corridors of space, and too expensive. Moreover, they are unable to efficiently separate and segregate different groups of data transmission lines according to function, application, or other criteria to make installation, repair and/or replacement more convenient.
There is a need, therefore, for a new and inexpensive cable tray system especially suited for computer and telecommunications applications, and particularly adapted for use in existing buildings where available corridors of space are limited, especially in the horizontal direction.
Another problem associated with conventional cable tray systems is that assembly and installation of the system requires the use of nut and bolt fasteners. The use of such fasteners is not only burdensome and time-consuming, but any misplacement or droppage of metal parts in a telecommunications area can cause significant disruptions and possible damage to sensitive electrical equipment.
There is a further need, therefore, for a support system which can be quickly and easily assembled and installed with little or no use of metal nut and bolt fasteners.